双Bowtie纳米光刻结构的聚焦特性研究

The investigation of focusing characteristic based on double Bowtie nano-lithography structure

Bowtie孔径结构已被广泛用于纳米直写光刻领域来获得超衍射聚焦光斑。然而,利用该结构获得的超衍射聚焦光斑呈椭圆形,影响了Bowtie结构的进一步应用。为了获得超衍射且圆形对称的聚焦光斑,本文提出了双Bowtie新型纳米光刻结构并利用Comsol软件仿真模拟了该结构的焦斑对称特性和电场增强特性。结果表明利用双Bowtie结构获得了圆形对称焦斑,并且出射面的电场强度得到了增强,是入射面电场强度的22倍。本文进一步将双Bowtie结构与金属/介质/金属结构相结合,使得局域增强后的透射光的传输距离(工作距)得到了显著延长。

Bowtie aperture has been widely applied in the realm of nanometer direct-writing lithography for obtaining focusing spots beyond the diffraction limit. However, the obtained spot is elliptic-shape for the Bowtie case, which impacts the applications of the Bowtie structure. Double Bowtie aperture, as a novel nano-lithography structure, is proposed to attain circle-symmetric focusing spots beyond diffraction limit. The results demonstrate that cir- cle-symmetry spots can be obtained, and the electric field intensity of transmission light is 22 times of that of inci- dence. By combining the double Bowtie structure with metal-insulator-metal, the propagation length of the enhanced transmission light is obviously prolonged.